1. Gyeongsangbuk-do Infectious Disease Control Division, Andong-si 36759, Gyeongsangbuk-do, Republic of Korea
2. Department of Preventive Medicine, College of Medicine, Dongguk University, Gyeongju 38066, Gyeongsangbuk-do, Republic of Korea
3. Gyeongsangbuk-do Center for Infectious Diseases Control & Prevention, Andong-si 36759, Gyeongsangbuk-do, Republic of Korea